Process of making soap



omPouNnS. 41 y July 2 1946 B. H. THURMAN 2,403,413

PRocEss oF MAKING soAP Filed llarch 23, 1942 Whe.

Patented July 2, 1946 PROCESS F MAKING SOAP Benjamin H. Thurman, Charlotte, N. C., assignor, by mesne assignments, to Benjamin Clayton, Houston, Tex., doing business as Refining,

Unincorporated applicati@ March 23, 1942, serial No.v 435,900

12 Claims. 1

This invention relates to a process of making soap and more particularly to a process by which soap is produced from glycerides and glycerine is liberated and recovered and in which a saponifying agent which does not react readily with glycerides may be employed.

The invention has particular utility in conjunction with the production of water insoluble soaps such as aluminum soaps. magnesium soaps, lead soaps and other soaps of polyvalent metals, although it may be employed to produce water soluble soaps such as alkali metal soaps, for example, sodium and potassium soaps even though compounds of alkali metals which do not react readily. with glycerides are employed as saponicatlonagents. It also has utility in the production of various soap mixtures which may contain both soluble and insoluble soaps. The soap making process of the present invention is capable of producing glycerine free anhydrous soaps or soaps containing any desired amounts of glycerine and water and may also include saponication in the presence of a lubricating oil or the addition of such oil to the resultant soaps preferably while the soap is in molten anhydrous form so as to produce lubricating greases.

The term "saponication is employed herein to mean a reaction in which soap is one of the products and is not intended to cover or embrace reactions involving de-esterication only of esters such as the splitting of glycerides without the formation of soap. Similarly the term saponifying agent is employed to mean an agent which reacts with fatty material to form soap irrespective vof whether any de-esterlflcation is involved. Y

In carrying out the process of the present invention, the glycerides are rst split so as to produce a mixture consisting essentially of fatty acids, glycerine and water. Saponification of the fatty acids is then rapidly produced under relatively high temperature conditions without prior separation of glycerine and water from the fatty acids. Under these conditionslv relatively inactive saponifying agents, which will not readily attack glycerides, rapidly convert the fatty acids into soap and any unsplit glycerides in the'glycerine-fatty acid mixture are reacted and their glycerine recovered even though the saponication agent is not sufliciently active for effective saponication of a material Consisting essentially of glycerides.

The glycerine and water may be separated from the resultant soap by vapOrZatiOn at relatively high temperatures so as to produce a molten substantially anhydrous glycerine free soap although a desired quantity of glycerine may be left in the soap if such glycerine is desired in the nalproduct. Also a desired amount of moisture may 'be reincorporated into the soap before discharge of the same from the process. A lubricating oil may be added to the materials prior to the vapor separating step or to the soap withdrawn lfrom the vaporizing step depending upon the nature of the lubricating oil and the temperatures employed in the vapor separating step. Th'e resultant soap may thus be discharged from the process as glycerine free anhydrous soap, as anhydrous soap containing glycerine, as anhydrous soap admixed with lubricating oil, or as anhydrous soap admixed with lubricating oil and glycerine, or a desired amount of water may be incorporated in the soap before itis discharged from the process, irrespective of whether the soap contains any other material such as glycerine or lubricating oil. In any case a substantially anhydrous soap which may or may not contain glycerine. lubricating oil or both, is at least an intermediate product in the process.

Anhydrous soaps of polyvalent metals usually have substantially lower melting points than anhydrous alkali metal soaps. Also glycerine may be substantially completely separated in vapor form from soaps of polyvalent metals at temperatures substantially below the melting point of anhydrous alkali metal soaps if the polyvalent metal soap or soap mixture is molten at such temperatures when anhydrous. The melting points of anhydrous alkali metal soaps 'are usually substantially above 550 F. and at such temperatures glycerine is quite rapidly decomposed in the presence of excesses of caustic alkali. At least 'slight excesses of saponifying agent are desirable in soap making processes to insure completion of the reaction. In general, glycerine may be substantially completely recovered in vapor form from soaps of polyvalent metals under vacuum conditions at temperatures below 550 and usually below 500 F., which temperatures do not cause appreciable destruction of glycerine even though excesses of sapOnifying agents are present. That is to say glycerine will substantially completely vaporlze from soap at 400 F. under` a vacuum of at least 28% inches of mercury if the soap or soap mixture is molten when anhydrous at that temperature. This is one of the primary reasons'why thc 5 present process has particular utility in the production of the lower melting point water insoluble soaps.

Alkali metal soaps may, however, be produced and glycerine recovered by the present invention without substantial destruction of glycerine even in the presence of excesses of alkali metal compounds if such excesses are non-caustic compounds of alkali metal, for example sodium carbonate, di-sodium phosphate, tri-sodium phosphate, etc. In such cases all of the saponifying agent may be a non-caustic alkali compound or the majority of the saponifying agent may be an alkali metal hydroxide so long as the caustic alkali is insulcient to provide an excess after the fatty material is completely saponified. The caustic alkali all reacts with the fatty material leaving the non-.caustic compOund to constitute the excess and such excess non-caustic compounds are much less destructive of glycerine at high temperatures than alkali.

By carrying out the glycerine vaporization step or saponification and glycerine vaporization steps in the presence of a lubricating oil which does not volatilize in the glycerine vaporization step, a soap mixture comprising an anhydrous mixture of soap and lubricating oil, which remains liquid in the vapor separating chamber at temperatures below the melting point of the anhydrous soap. may be produced so as to lower the temperature necessary in the vapor separating chamber for effective separation of glycerine vapor. Also, by emplaying mixtures ofcompounds of alkali metals and compoundsv of polyvalent metals as the saponifying agent, anhydrous mixed soaps of alkali metals and polyvalent metals, which have lower melting points than anhydrous alkali metal soaps, may be produced so as to lower the effective glycerine vaporizing temperatures. Depending upon the product desired, either or both of these operations may be employed to produce soaps containing substantial amounts of alkali metal soaps and containing an excess of alkali while reducing glycerine destruction. Also if a polyvalent metal soap containing a high boiling point lubricating oil is desired, the vaporization step can be carried out in the presence of the lubricating oil to reduce the melting point of the resulting soap mixture so as to enable glycerine recovery at a lower temperature. In many cases substantially complete separation of glycerine in vapor form can be obtained at temperatures not substantially above 400 F. The employment of a light hydrocarbon which vaporizes during the vaporization step, in any case, assists in releasing glycerine vapor from the molten soap or soap mixturel thus enabling glycerine vaporization to be carried on at temperatures not substantially above the melting point of the anhydrous soap or soap mixture so long as this temperature is not substantially below 400 F.

An object of the present invention is, therefore, to provide an improved process of producing soap from glycerides in which saponifying agents which do not react readily with glycerides -are employed.

A still further object of the invention is to provide a complete process in which an insoluble soap is made from glycerides and in which a saponifying agent which does notreadily react with glyc.- erides is employed.

Other objects and advantages of the invention will appear in the following description of preferred embodiments of the invention made in connection with the attached drawing oi which Fig. 1 is a schematic diagram of an apparatus for carrying out the process of the present invention; and

Fig. 2 is a view similar to Fig. 1 illustrating a modification of certain of the apparatus of Fig. 1.

In one embodiment of the present invention, suitable apparatus for which is shown in Fig. l, glycerides are rst split into glycerine and fatty acids in a batch splitting step. Since the remainder of the process may be carried out in a continuous manner, a plurality of reaction chambers, for example, three reaction chambers I0, II and I2 may be provided for producing a mixture of fatty acids, glycerine and water from glycerides by the reaction between the glycerides and water,

Another object of the invention is to provide an A usually in the presence o f a catalyst. Reaction chambers I0, I I and I2 may be of the autoclave type for operation under relatively high temperatures and pressures, for example to 150 pounds per square inch and at a temperature approximately at the boiling point of water at the pressure employed. In such processes, suitable catalyst are ordinarily employed such as small amounts of zinc oxide, calcium oxide, magnesium oxide, caustic soda, sodium acid sulphate, sulfuric acid, etc. It is preferred, however, to carry on the splitting operation 'in a batch operation at substantially atmospheric pressure, an example of which is the Twitchell" method which employs sulfuric acid and benzene sulfonic acids or naphthalene sulfonic acids as a catalyst at temperatures in the neighborhood of 212 F. Low temperature enzyme or lypolytic splitting steps are particularly adapted to the present invention. Although this type of splitting is known to the art and produces rapid splitting at low temperatures and light colored products, it has not been employed to any considerable extent because of the dimculty of resolving extremely troublesome emulsions produced in the splitting step. Such emulsions have been dilcult to handle even 1n evaporation or distillation steps for separating glycerine, fatty acids and water. In the present process where saponiication of the fatty'acids is produced prior to glycerine separation athigh temperatures, this diiliculty is eliminated.

The reaction chambers I0, Il and I2 may be closed or substantially closed to the atmosphere and provided with an agitator I3 and a. heating coil I4. The glycerid to be split may be introduced into the chambers through a pipe Il, and water containing the catalyst or enzyme introduced into the reaction chambers through the pipe I1. Although such reaction chambers need not be closed from the atmosphere for operations at substantially atmospheric pressure, it is desirable to maintain the reaction mass out of contact with the atmosphere and for this purpose closed reaction chambers may be provided with a vent pipe I8 which may have a suitable pressure relief valve so that a slight super-atmospheric pressure may be maintained in the reaction chambers, if desired, and any steam or water vapor generated therein vented to the atmosphere.

Depending upon the nature of the glyceride emuu vill-.Huw u u COMDUNDS ployed the nature of the splitting operation and the amount of water relative to the amount of glyceride, glycerides can be substantially completely split by the Twitchell method at temperatures between 210" and 220 F. in periods ranging between four and twelve hours and in a somewhat shorter time and at lower temperatures by the enzymc method. A large excess of water over that necessary to react with the glycerides is preferably employed to force the splitting reaction toward completion and the resulting mixture consists essentially of fatty acids, glycerine and water. Any small amounts of unsplit glycerides which may be present are split and the fatty acids saponified in succeeding steps of the process.

By providing a plurality of reaction chambers, the reacted mixture may be withdrawn from one of the chambers while splitting is progressing in the other chambers. -For example, the mixture of fatty acids, glycerine and water may be drawn from the tank I0 through the pipe I9 by open.

ing the valve 2| while the valves 22 and 23 are maintained in closed condition. This mixture may be Withdrawn by means of a proportioning pump 24 and delivered through heat exchanger 2B to a mixer 21. A saponifying agent, for example a slurry of aluminum hydroxide, if aluminum soap is desired in the final product, may be withdrawn from a tank 28 by meansof a pump 29 and delivered through a heat exchanger 3l to the mixer 21. The tank 28 preferably contains an agitator 32 driven from any suitable source of power for maintaining the solution or slurry ofl saponifying agent in uniform condition, if necessary, and may also be provided with a heating coil 33 to heat the saponifying agent. Thus the temperature of the saponif'ying agent may be maintained at temperatures up to those approaching the boiling point of water. or even higher so as to increase the solubility of the saponifying agent in water, if the tank 28 is closed and capable of being operated under pressure. Since the mixture including fatty acids and glycerine usually contains a' large excess of water the saponifying agent solution or slurry may be as concentrated as it is possible to maintain in a, uniform pumpable admixture.

If it is desired to incorporate a lubricating oil into the finished product, this may be done prior to saponication, for example by withdrawing a stream of such lubricating oil from a tank 34 by means of a proportioning pump 35 and passing the same through a heat. exchanger 31 to the mixer 21. This operation is possible when the lubricating oil has a boiling point substantially higher than any temperature reached in the vaporizing step of the process hereafter described. Even if no lubricating oil is desired in the final product or the lubricating oil desired in the final product has a boiling point too low to be introduced prior to separation of water and glycerine by va rization, it is advantageous to incorporate a. lig t hydrocarbon, such as a hydrocarbon in the kerosene or fuel oil ringe, to assist in liberating glycerine vapors in 'the vapor separation step. Instead of supplying the lubricating oil or light hydrocarbon or both from a separate tank 34 with a proportioning pump 35, either or both may be admixed with the products of the splitting operation in the reaction chambers I0, Il and l2 preferably just prior to starting the delivery of such material to the saponication step of the process. For example, the lubricating oil or light hydrocarbon or both may be introduced through the pipe I6 or either or both may be 6 admixed with the saponifyins agent in the tank 28. In such case the tank 34 with associated proportioning pump 35 and heat exchanger 31 may Abe eliminated. If alight hydrocarbon is employed the most important consideration is that it be present in the vapor separating step to aid in the liberation of glycerine vapor and it may, therefore, be added at any time prior to the introduction of the materials into the vapor separation step. If a lubricating oil which has a boiling point substantially above that required for glycerine vaporization is desired in the final product, it .is likewise desirably added at some time prior to the introduction of the materials into the vapor separation step.

The pumps 24, 29 and 35 may be driven by a variable speed electric motor 38 directly driving pump 24 with a variable speed device 39 connected between the motor and the pump 29 and a variable speed device 40 connected between the pump 24 and the pump 35. This proportioning apparatus is shown merely by way of example and any suitable proportioning apparatus known to the art may be employed, the preferred proportioning apparatus being of the type shown in the patent to Thurman No. 2,142,062 granted December 27, 1938. The mixer 21 may be any suitable type of flow mixer, for example, one of the type shown in the patent to Thurman referred to above but may be a closed mechanical mixer. The heat exchangers 25, 3| and 31 may likewise be of any suitable type capable of rapidly heating or cooling materials in rapid stream ow and preferably include a coil 4| through which the material to be heated or cooled is passed, surrounded by a casing 42 through which any deilt'i heating or cooling medium may be circu- By preheating the various materials delivered to the mixer 21 in the heat exchangers 26, 3| and 31 to a relatively high temperature. for example temperatures in the neighborhood of 300" F. even such relatively inactive saponifying agents as aluminum hydroxide are caused to react rapidly With the fatty acids in the mixture delivered to the mixer from the glyceride splitting step. In order to provide time for completion of the reaction and to raise the temperature still further, the mixture from the mixer 21 may be passed through one or more heat exchangers 43 and 44. A pump 45, driven from any suitable 'source of power,.may be employed to produce further mixing between the heat exchangers 43 and 44 and to assist in forcing the mixture undergoing saponification through the system. the saponication reaction will be substantially completed in the heat exchanger 43 4and the last heat exchanger 44 will be employed to introduce further heat into the mixture entering the vapor se'paration step. The pressure in heat exchanger 43 will ordinarily be suciently high to prevent any substantial formation of vapor but the pressure in the heat exchanger 44 may be sufliciently low to enable substantial amounts of water vapor or light hydrocarbon vapors, if present, to be generated. The temperature reached in the heat exchanger 43 will ordinarily vary between 350 and 400 F'. depending upon the nature of the glyceride and saponifying agent employed while the temperature reached in the heat exchanger 44 will ordinarily vary between 400 and 550 F. but in mos-.t cases will range between 420 t0 500" F. also depending upon the nature of the saponifying agent and the glyceride employed.

The substantially completely saponied mix- In general 2,4os,41s

7 ture of soap. slycerine, water and vapors as well as lubricating oil or light hydrocarbon, if present, is discharged into a vapor separating chamber 46 through nozzles 41 so as to flow down the inclined lower walls 48 of the vapor separating chamber. The walls 48 are preferably maintainedat a temperature at least as high as that of the entering materials, for example by means of a heating jacket 49 through which any desired heating medium may be circulated. By operating the vapor separating chamber 4B at a temperature above the melting point of the soap or soap mixture when anhydrous and maintaining a relatively high vacuum therein, water vapors, glycerine vapors and vapors of light hydrocarbon, if employed, may be withdrawn from the vaporv separating chamber through a pipe I. It has been found that if the soap or soap mixture deposited in the vapor separating chamber remains molten that glycerine can be substantially completely separated therefrom along with water and other vapors at temperatures as low as approximately 400 F. with a vacuum ranging from 281/2 to 29 inches in mercury. This relativelylow temperature operation is possible with many insoluble soaps such as aluminum, calcium or magnesium soaps of the usual fatty acids encountered in glycerides as these soaps have melting points substantially lower than sodium or potassium soaps. I'he presence of a lubricating oil which does not volatilize in the vapor separating chamber will also in most cases reduce the melting point of the soap mixture. A thin film of molten material owing downl the walls of the vapor separating chamber 4l causes the glycerlne vapor to be relatively easily liberated.

The vapors withdrawn from the vapor separating chamber 46 through the pipe 5| may be delivered to one or more oondensers 52 and Il connected to suitable receivers 54 and 50 respectively, As illustrated, a plurality of condensers canbe employed for fractionally condensing the various materials such as water, glycerine and light hydrocarbon, the number of condensers and receivers employed depending upon the number of l fractions desired. A fractionating column may be employed instead of a plurality of condensers. If the saponifying agent employed is a carbonate so that relatively large amounts of carbon dioxide are present lin the vapors withdrawn from the vapor separating chamber, a carbon dioxide absorption tower 51 may be connected to the last receiver 56 so as to absorb the carbon dioxide and relieve the load upon the vacuum pump 5l employed to maintain a vacuum in the various condensers, receivers and vapor separating chamber. A suitable carbon dioxide absorbing agent is an aqueous solution of sodium hydroxide which combines with the carbon dioxide to form sodium carbonate, but other known agents such as certain amines or ethanolamines may be ernployed.

In general it is preferred to maintain .a pool of molten anhydrous soap in the lower portion of the vapor separating chamber 46 and a stream of this molten anhydrous soap may be withdrawn from the vapor `separating chamber by means of a pump 6I. If the resulting soap is to be employed in the manufacture oi' greases and the lubricating oil employed therein is' not added prior to saponincation it may be' added to the stream of molten anhydrous soap. for example by withdrawing a stream of lubricating 40 oil.

8 i delivering the same to a iiow mixer I4 to which the stream of molten anhydrous soap from the vapor separating chamber 4l may also be delivered. If necessary to maintain the resulting 5 mixture of soap in fluid form after admixture of the lubricating oil. the lubricating oil may be passed through heat exchanger 66 to increase its temperature before being delivered to the mixer 64. The heat exchanger 6B as well as 10 the heat exchangers 43 and 44, heretofore referred to, may be of the same type as the heat exchangers 2B, Il and 31. The mixer 54 Amay be of any suitable type such as described with reference to mixer 21. The mixture of anhydrous soap and lubricating oil may be delivered from the mixer B4 into any suitable cooling device, for example a screw conveyor B9 provided with a cooling Jacket 1|, and the cooled material discharged from the process. Such screw conveyor may be of the type shown in the patent to Thurman No. 2,190,615 granted February 13, 1940.

Il.' the product contains a substantial amount of lubricating oil so that a grease is produced which flows readily after cooling, it is apparent that other types of heat exchangers, for example one similar to the heat exchanger I1, may be employed to cool the grease before discharge to the atmosphere.

With certain types of greases,.for example, calcium greases, a slight amount offmoisture is desirable in the nnished product and one way of incorporating this moisture into the product is to mix a small amount of water with the lubricating oil in the tank. l2, the mixture being maintained uniform by means of an agitator 12. If no j lubricating oil is added to'the soap at this stage of the process and a small amount of moisture is desired in the finished product, it may be added from the tank 02 in the absence of lubricating If no lubricating oil is to be added to the liquid product from the; vapor separating chamber 48, it is apparent that the screw conveyor 09' can be positioned directly below the vapor sepa- Y rating chamber to receive the molten material 45 directly therefrom withoutthe employment of a pump Il., It is also possible to introduce the lubricating oil. water or both directly into such a screw conveyor.

Instead of employing the batch splitting steps so described with reference to the reaction cham- ,bers I 0, H and l2 of Fig. 1 a continuous splitting operation producing substantially the same type of mixtureas that produced in the splitting steps described with reference to F18. 1 maybe employed.L For example, as shown in Fig. 2 glycerides may be withdrawn from a tank 1I by means of a proportioning pump 14 and passed through a heat exchanger 1I to a mixer 11. Water or water containing a suitable catalyst may be withdrawn from a tank 'I8 by means of a proportion-V l 'ing pump 10 and passed through a heat exchanger Il to the mixer 11. The water and glycerides may be heated to relatively high temperatures under pressure in the heat exchangers Il and 1l, respectively, for example temperatures between 300 and 400 I". The mixer 11 may be of any suitable type such as described with reference to the mixer 21 of Fig. 1 and the resulting mixture may be passed through a plurality of heat exchangers, for example heat exchangers l2 and 83 wherein the mixture is subjected to relatively high' temperatures, for example temperatures up to 600 F. at high pressures, for example pressures as high as 1000 to 1500 pounds per oil from the tank 62 by means of a pump 83 and 'i5 square inch. Under these .conditions the glycer- CWDOUNDS,

ldes react rapidly with the water to liberate fatty acids and glycerine.

A large excess of water is ordinarily employed over that necessary to react with theV glycerides so as to carry the reaction to substantial completion, an amount of water equal in amount to the amount of glycerides having been found satisfactory. Since the temperature of the mixture discharged from the heat exchanger 83 will ordinarily be higher than that desired in the saponifying reaction, another heat exchanger 84 may be employed to cool the resulting mixture down to temperatures, for example in the neighborhood of 400 to 450 F. This mixture may be supplied to the mixer 21 of Fig, l, for example by substituting the proportionng pumps 14 and 'I9 of Fig. 2 for the proportiom'ng pump 24 of Fig. 1. It is entirely possible to make batch mixtures of the glycerine and water and splitting catalyst if used, which are then delivered in succession through a series of heat exchangers such as the heat exchangers 82 and 83 so as to eliminate the proportioning pumps 14 and 'I9 and mixer 11.

The products of the saponication process are substantially the same irrespective of whether the glycerides are split in a batch operation as described with reference to Fig. 1 or a continuous operation as described with reference to Fig. 2. In any event the glycerides are rst split to obtain a. mixture of glycerine and fatty acids in water which may contain some unsplit glycerides, and a saponifying agent is then added to saponify the fatty acids and any unsplit glycerides. Glycerine is then recovered or partially recovered in vapor 'form from the resulting mixture of soap, glycerine and water by separating glycerine and water vapors from the soap so as to produce a molten substantially anhydrous soap. If a light hydrocarbon is present during the vaporization step, vapors of a light hydrocarbon will likewise be removed in the vapor separation step and assist in liberating glycerine vapors so as to somewhat lower the necessary vaporizing temperature.

As stated above. the present process finds its chief utility in the production of insoluble soaps such as aluminumy magnesium, calcium, lead, etc., soaps. The hydroxides or other alkaline compounds of materials forming insoluble soaps in general react slowly, if at all, with glycerides, although calcium hydroxide reacts fairly rapidly. Nevertheless, the present process can be advantageously employed with calcium hydroxide as the saponifying agent as substantially complete saponification can -be more readily obtained. The process can also be employed for the production of soluble soaps such as sodium or potassium soaps. If the hydroxides of these materials are employed as the saponifying agent the hydroxide readily saponiiies with the glycerides. However, if carbonates or other alkaline compounds of the alkali metals which do not react readily with glycerides are employed as a saponifying agent, the present Aprocess is advantageous in that substantially complete saponication is easily obtained. The use of such noncaustic compounds of the alkali metals is advantageous as substantially no glycerine destruction occurs even if an excess of the saponifying agent is employed and the relatively high temperatures, for example temperatures about 550 F., necessary for producing an anhydrous molten alkali metal soap are used in the process.

When hydroxide or other alkaline compounds of elements producing insoluble soaps are employed as the saponifying agent the vapor sepa- 10 ration can usually be carried on at a substantially lower temperature than is the case whe` alkali metal compounds are employed as the saponifying agent. The insoluble soaps in general have a substantially lower melting point than the soaps of alkali metals so that a molten soap is produced at temperatures not substantially above 400 F. As discussed above, glycerine can be separated in vapor form at such temperatures if the soap produced is molten. Thus the present process enables insoluble soaps either in substantially pure form or admixed with a lubricating oil to form a grease to be produced rapidly from glycerides while at the same time glycerine is recovered. By fractionally condensing this glycerine it may be recovered in concentrated substantially pure form. It is of course apparent that if any glycerine is desired in the soap product that the temperature in the vapor separating chamber may be somewhat lower or the pressure somewhat increased so as to prevent vaporization of all or a part of the glycerine. Nevertheless substantially all of the water can be removed from the soap even ifv substantial amounts of glycerine are left therein so that an anhydrous soap or soap mixture is produced. If water is desired as a component of the nished product it can be added to the heated anhydrous soap mixture before discharge from the process.

While I have described the preferred embodiments of my invention, it is understood that it may be varied within the scope of the following claims:

l. The process of making soap and recovering glycerine from glycerides, which comprises, splitting said glycerides lo produce a mixture of glycerine, fatty acids anu water, adding a saponifying agent to said mixture to convert said fatty acids into soap, and separating glycerine from said soap.

2. The process of making soap and recovering glycerine from glycerides, which comprises, splitting said glycerides to produce a mixture of glycerine, fatty acids and water, adding a saponifying agent to said mixture to convert said fatty acids into soap, and separating water and glycerine from said soap by vaporizing said water and glycerine.

3. The process of making soap and recovering glycerine from glycerides, which comprises, splitting said glycerides to produce a mixture of glycerine, fatty acids and water, adding a non-caustic saponifying agent to said mixture to convert said fatty acids into soap, and separating glycerine in vapor form from said soap.

4. The process of making soap and recovering glycerine from glycerides, which comprises, splitting said glycerides to produce a mixture of glycerine, fatty acids and water, mixing a flowing stream of said mixture with a stream of saponifying agent so as to convert said fatty acids into soap, delivering the resulting stream into a vapor separating zone at a temperature sutliciently high to vaporize said glycerine. separating glycerine in vapor form from said soap insaid vapor separting zone. and separately withdrawing glycerine and soap from said vapor separating zone.

1o. The process of making soap and recovering glycerine from glycerides, which comprises, splitting said-glycerides to produce a mixture of glycerine, fatty acids and water, adding a saponifying agent to said mixture to convert said fatty acids into soap, delivering the resulting mixture into a vapor separating zone at a temperature sufficientll ly high to vaporize said glycerine while said resulting mixture is admixed with a lubricating oil which does not vaporize in said vapor separating zone, maintaining said zone under vacuum conditions and at a temperature suiciently high to cause glycerine to separate from said soap in vapor form, and'separately withdrawing glycerine vapor and soap admixed with said lubricating oil from said zone.

6. The process of making soap and recovering glycerine from glycerides, which comprises, splitting said glycerides to produce a mixture of glycerine, fatty acids and water, adding a saponifying agent consisting essentially of a polyvalent metal hydroxide to said mixture to convert said fatty acids into soap, delivering the resulting mixture into a vapor separating zone at a temperature suiiiciently high to vaporize said glycerine while said resulting mixture is admixed with a lubricating oil which does not vaporize in said vapor separating zone. maintaining said zone under vacuum conditions and at a temperature'sufiiciently high tc cause glycerine to separate from said soap in vapor form, and separately withdrawing glycerine vapor and soap admixed with said lubricating oil from said zone.

7. The process of making soap and recovering glycerine from glycerldes, which comprises, splitting said glycerides to produce a mixture of -glycerine, fatty acids and water, adding a saponifying agent consisting essentially o'f an alkaline earth metal hydroxide to said mixture to convert said fatty acids into soap, delivering the resulting mixtureinto a vapor separating zone at a temperature suidciently high to vaporize said glycerine while said resulting mixture is admixed with a lubricating oil which does not vaporize in said vapor separating zone, maintaining said zone under vacuum conditions and at a temperature sufiiciently high to cause glycerine to separate from said soap in vapor form, and separately withdrawing glycerine vapor and soap admixed with said lubricating oil from said zone.

8. 'I'he process of making soap and recovering glycerine from glycerides, which comprises, splitting said gLvcerides to produce a mixture of glycerine, fatty acids and water, adding a saponifying agent consisting essentially of a compound of an alkaline earth metal to said mixture to convert said fatty acids into soap, and separating water and glycerine from said soap by vapory izing said water and glycerine.

9. The process of making soap and recovering glycerine from glycerides, which comprises. splitting said glycerides to produce a mixture ot glycerine, fatty acids and water. mixing a nowing stream oi' said mixture with a stream of saponifying agent comprising a polyvalent metal hydroxide so as to convert said fatty acids into soap, delivering the resulting stream into a vapor separating zone at a temperature sufllciently high to vaporize said glycerine, separating glycerine in vapor form from said soap in said vapor separating zone, and separately withdrawing glycerine and soap from said vapor separating zone.

10. The process of making soap and recovering glycerine from glycerides, which comprises, splitting said glycerides to produce a mixture of glycerine, fatty acids and water, mixing a. owing stream of said mixture with a stream of saponifying agent comprising a polyvalent metal hydroxide so as to convert said fatty acids into soap,

,delivering the resulting stream into a vapor separating zone at a temperature suiiiciently high to vaporize said glycerine, separating glycerine in vapor form from said soap in said vapor separating zone, separately withdrawing glycerine and soap from said vapor separating zone, and adding a lubricating oil to said soap during withdrawal thereof.

1l. The process of making soap and recovering glycerine from glycerides, which comprises, splitting said glycerides to produce a mixture of glycerine, fatty acids and water, by reacting water with said glycerides at a relatively low temperature in the presence of an enzyme, mixing ailowing stream of said mixture with a stream of saponifying agent so as to convert said fatty acids into soap, delivering the resulting stream into a vapor separating zone at a temperature sulciently high to vaporize said glycerine, separating glycerine in vapor form from said soap in said vapor separating zone, and separately withdrawing glycerine and soap from said vapor separatins zone.

12. The process of making soap and recovering glycerine from glycerides, which comprises, splitting said glycerides 'to produce a mixture of glycerine, fatty acids and water, by reacting said glycerides with water in the presence of a splitting agent at a temperature not substantially above the boiling point of water, mixing a flowing stream of said mixture with a stream of saponifying agent so as toconvert said fatty acids into soap, delivering the resulting stream into a vapor separating zone at a temperature sufciently high to vaporize said glycerine, separating glycerine in vapor form from said soap in said vapor separating zone, and separately withdrawing glycerine and soap from said vapor separating zone.

BENJAMIN H. THURMAN. 

